<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    /* .box{
      font-size: 10px;
    }
    .wrap{
      width: 10vw;
      height: 10vh;
      background-color: red;
    } */
    *{
      margin: 0;padding: 0;
      font-size: 0;
    }
    .box{
      width: 25vw;
      display: inline-block;
      height: 100px;
      background-color: pink;
    }

    @media screen and (max-width: 1000px) {
      .box{
        width: calc(100vw/3);
      }
    }
  </style>
</head>
<body>
  <div class="box"></div>
  <div class="box"></div>
  <div class="box"></div>
  <div class="box"></div>
  <div class="box"></div>
  <div class="box"></div>
</body>
</html>